Herbicidal compositions and methods utilizing thiadiazolis ureas

ABSTRACT

wherein R1 represents a lower Alpha -halogen alkyl radical R2 and R3 each independently represent hydrogen or a lower alkyl radical R4 represents a lower alkyl radical that is unsubstituted or substituted by cyano or alkoxy, a cycloalkyl radical or alkinyl radical X represents oxygen or sulphur AND PROCESSES FOR THEIR PREPARATION ARE GIVEN. These ureas have herbicidal activity and compositions containing them can be used for the control of gramineous and dicotyledonous weeds. New ureas of the Formula

Moser et a1.

Nov. 4, 1975 1 HERBICIDAL COMPOSITIONS AND METHODS UTILIZING THIADIAZOLIS UREAS [75] Inventors: Hans Moser, Basel; Christian Vogel,

Binningen, both of Switzerland [73] Assignee: Ciba-Geigy Corporation, Ardsley,

[22] Filed: Apr. 25, 1974 [21] Appl. No.: 464,088

Related U.S. Application Data [62] Division of Ser. No. 123,446, March 11, 197], Pat.

[30] Foreign Application Priority Data Mar. 19, 1970 Switzerland 4159/70 [52] US. Cl 71/90; 71/92 [51] Int. C1. AOIN 9/12 [58] Field of Search 71/90, 92

[56] References Cited UNITED STATES PATENTS 3,565,901 2/1971 Cebalo 260/306.8

3,673,203 6/1972 Miller 71/90 3,686,198 8/1972 Metzger et al.... 71/90 3,784,555 1/1974 Cebalo et a1 71/90 3,840,551 10/1974 Sasse et a1. 71/90 Primary Examiner.lames 0. Thomas, Jr. Attorney, Agent, or Firm-l-Iarry Falber [57] ABSTRACT New ureas of the Formula wherein R represents a lower a-halogen alkyl radical R and R each independently represent hydrogen or a lower alkyl radical R represents a lower alkyl radical that is unsubstituted or substituted by cyano or alkoxy, a cycloalkyl radical or alkinyl radical X represents oxygen or sulphur and processes for their preparation are given. These ureas have herbicidal activity and compositions containing them can be used for the control of gramineous and dicotyledonous weeds.

15 Claims, No Drawings HERBICIDAL COMPOSITIONS AND METHODS UTILIZING THIADIAZOLIS UREAS This is a division of application Ser. No. 123,446, filed on Mar. ll, 1971, now US. Pat. No. 3,822,280.

DESCRIPTION OF THE INVENTION In this formula:

R represents a lower a-halogen-alkyl radical,

R2 and R each indepentently represent hydrogen or a lower alkyl radical,

R represents a lower alkyl radical that is unsubstituted or substituted by cyano or alkoxy, a cycloalkyl radical, an alkoxy radical, an alkenyl, halogenoalkenyl or alkinyl radical,

X represents oxygen or sulphur.

In general Formula l, as lower alkyl radicals R R R and R are meant straight or branched chain radicals having 1 to 6 carbon atoms such as, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl as well as pentyl and hexyl radicals. The lower a-halogen alkyl radicals R contain 1 to 3 halogen atoms in the first carbon atom and comprise radicals such as chloromethyl, dichloromethyl, trichloromethyl, trifluoromethyl, fluorodichloromethyl, bromomethyl, dibromomethyl, a-chloroethyl, a,a-dichloroethyl, a-chlorom-propyl, l l -dichloro-3-methylbutyl, etc. A cycloalkyl radical R, has 3 to 10 carbon atoms, preferably 3 to 6 carbon atoms; suitable are the cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl radicals. Such a cycloalkyl radical can be monoor polysubstituted by lower alkyl, preferably by methyl and ethyl. An alkoxy radical R is one having 1 to 4 carbon atoms, for example methoxy, ethoxy, n-propoxy, iso propoxy, or a butoxy radical. Such alkoxy radicals also designate the substituents of a lower alkyl radical R Suitable as alkenyl and halogenoalkenyl radicals R are, in particular, the allyl, methallyl or a propenyl radi- (Ill -NHR-,

either with a halogeno-carbonic acid ester or wi phosgene in the presence of an acid-binding agent int a carbamic acid derivative and reacting this with z amine of the Formula III:

Chloro-carbonic acid phenyl esters and chloro-thioca bonic acid esters are preferred as halogeno-carbon acid esters; whereby the following carbamic acids, ft

example, are obtained in good yields as intermedia products:

N- 3-trifluoromethyll',2,4-oxadiazolyl( 5 )]carbamic acid-phenyl ester N-[ 3-trifluoromethyll ,2,4-thiadiazolyl(5 ]-carbamic acid-phenyl ester N- 3-trichloromethyl l ,2 ,4-oxadiazolyl(5 ]-carbamic acid-phenyl ester N-[ 3trifluoromethyl- 1,2,4-thiadiazolyl(5 )]-carbamic acid-phenyl ester N-[ 3-dichloromethyll,2,4-thiadiazolyl(5 )]-carbamic acid-phenyl ester as well as the corresponding N-[ 3-trihalogenometh yll ,2,4-oxadiazolyl( 5 )]carbamoyl chlorides and N- 3-dihalogenomethyll ,2,4-thiadiazolyl( 5 )]-carbamoyl chlorides.

and thi As acid-binding agents, preferably tertiary aminr such as trialkyl amines, pyridine bases, etc., are used 1 well as inorganic bases such as the hydroxides and ca bamates of alkali and alkaline earth metals. The rear tion temperatures are between 0 and 150C.

The reaction of the resultant carbamic acid deriv, tives with a primary or secondary amine of the formu III takes place at temperatures between 40 ar l50C,'preferably between 0 and C.

The new ureas of Formula I in which R represen hydrogen can be produced by a modification of tl process according to the invention by reacting z amine of Formula II with an isocyanate of the formu R NCO.

The processes described are performed in the pre ence of solvents or diluents which are inert to the rea tion components, suitable are, for example, the follo\ ing: aliphatic and aromatic hydrocarbons and halog nated hydrocarbons, in particular benzene, toluene, x lene, chloroform, chlorobenzene; ether and ether-tyt compounds, e.g., dioxane, tetrahydrofuran; N,N-di2 kyl amides such as dimethyl formamide, diethyl forr amide; ketones such as, e.g., acetone, methyl ethyl ke tone, cyclohexanone; nitriles such as acetonitrile, et

Furthermore, the new ureas of the Formula I are 0 tained by reacting an amine of the Formula II with carbamoyl halide of the Formula herein R represents a lower alkyl radical, and R, has 3 meanings given for Formula I, in the presenceof id-binding agents.

Some of the amines of Formula II are known, the othcan be produced by known methods. The amines of irmula II in which X represents oxygen, can be proced by reacting trichloroor trifluoro-acetamidine with cyanogen bromide, or (b) with trichloroacethydride to the corresponding 3-trihalogenomethyltrichloromethyl-l,2,4-oxadia2ole and subsequently ing an amine of the Formula NH R to replace the triloromethyl group by the group NHR For these actions, condensing agents are required, such as for ample tertiary amines, N,N-dialkyl formamicle, inornic bases, etc. As solvents or diluents, in addition to a above-mentioned, also alkanols, e.g., methanol, nano] and isopropanol may be used.

The new ureas of Formula I have excellent herbicidal operties and are suitable for the control of gramine- .s and latifoliate weeds in the most varied cultivated lntations. Even annual and perenial weeds which are ep rooted and difficult to control are damaged in air growth or destroyed by these active substances. 1118 the new ureas of Formula I can be employed in w concentrations for the selective control of weeds, r example for the control of chamomile varieties *Iatricaria spp.), Galium aparine, wild parsnip (Pasiaca sativa), pig weed varieties, e.g., Amaranthus p., mustard varieties (Sinapis spp.), grasses such as :hinochloa spp., Lolium spp., millet varieties (Pani- Active ingredients:

cum spp.), in grain, maize, soya bean, sorghum, cotton, root and tuber crops, and fodder plantations. The ureas of Formula I may be applied before emergence of the plants (preemergence) and also after emergence of the plants (postemergence). In high concentrations, i.e., above 5 kg of active substance per hectare, the new active substances can be used for the complete destruction and prevention of unwanted plant growth.

The herbicidal effect of the active substances according to the invention was determined by the following tests:

I. Herbicidal effect before emergence of the plants a. The active ingredients are mixed with the soil in a seed bed in a concentration of 100 mg of active ingredient per liter of soil. The following test plants were sown in soil (seed trays):

oats (avena sativa), Italian rye-grass (Lolium multiflorum), millet (Setaria italica), mustard (Sinapis alba), vetch (Vicia sativa), tomato (Solanum lycopersicum).

The trays are then kept in greenhouse at 22-25C and -70 humidity. The test is evaluated after 20 days according to the following scale of 9:

l plants dead 2-4 intermediate stages of damage (above 50 5 50 damage 6-8 intermediate stage of slight damage (below 50 9 plants undamaged control.

Millet Vetch Tomato Oats Rye-grass M usta rd -continued Active ingredients: Outs Rye-g russ Millet Mustard Vetch Tomato thiudiazolyH 5) ]-N.N'.N'- I 2 2 trimethyI-ureu N-[3-dichloromelhyl-L2A b. Directly after sowing the test plants, the active sub stances are applied to the surface of the soil as an aqueous suspension abtained from a 25 wettable powder. The seed trays are then kept at 22-23C and 50-70 relative humidity. After 28 days the test is evaluated. The following test plants were used:

Lolium multiflorum Setaria italica Echinochloa crus galli Sinapis alba Galium aparine Pastinaca sativa Poa trivialis Alopecurus myosuroides Digitaria sangualis lpomoea purpurea Vicia sativa The amounts applied in this test are found in the following table. The following scale of 9 was used for the evaluation:

1 plants dead 7 2-4 intermediary stages of damage (above 50 5 50 damage 6-8 intermediary stage of slight damage (below 50 9 plants undamaged control Composition of the 25 wettable powder:

25 parts of active substance, IO parts of sodium aluminium silicate, 0.6 part of sodium dibutylnaphthylsulphonate. 1.0 part of naphthalene sulp honic acid/formaldehyde condensation product 3:2:'l,"63.4 parts of kaolin. These wettable powders are suspended in an I I l I l l amount of water corresponding to I000 liters per hectare.

The following compounds have been tested as active substances:

1. N-[ 3-trifluoromethyl-I ,2,4-thiadiazolyl( 5 )]-N,N dimethyl-urea 45 N'-dimethyl-urea 3. N- 3-trifluoromethyll ,2,4-thiadiazolyl( 5 )]-N methyl-N '-methoxy-urea 1 4. N[ 3-trifluoromethyll ,2,4-thiadiazolyl(5 )]-N- ethyl-N'-methyl-urea 5. N- 3-trifluorome thyl- I ,2,4-thiadiazolyl( 5 )]-N N'-dimethyl-urea 6. N- 3-dichIoromethyl-l ,2,4-thiadiazolyl( 5 )]-N N'-dimethyl-urea 7. N-[ 3-dichloromethyll ,2,4-thiadiazolyl( 5 ]-N 55 methyl-urea (Known from the Dutch patent specification open to Alopecurus myosuroides public inspection N0 68,l 3437 (Bayer) Setaria italica active amount Alopeeurus Digilaria sanguin.

myos

m 4 mm m u L m UH m H g p pk m 3 m m 0 SN in U S Z l l l l l 9uo375. 722752543 active substance applied lpomoea Vicia in kg/na oats maize purpurea sativa wheat ermon I Jsv s aviga 5 5 5 5 124174 71 .1 ii 0 Q 0 0 0 Digitar iasanguinalis Arnaranthns retroflex as 'Papavcr rhoeas i Sinapis'alba In seed trays, oats, wheat and maize as culture rop were sown together with the following weeds:

Matricaria chamomilla Lolium multiflorum Matrica r11 chamorn ill 10 The following compounds were tested as active sul stance:

Sinapis alba N-[ 3-trifluoromethyll ,2,4-thiadiazolyl-( 5 N,N"-dimethy1-urea N 3-trif1uoromethyll ,2,4-thiadiazoly1( 5 ]-N' N'-dimethyl-urea N-[ 3-trifluoromethyl- 1 ,2,4-thiadiazolyl( 5 ]-N methyl-urea N- 3-trifiuoromethyl- 1 ,2,4-thiadiazolyl( 5 ]-N 10 methyl-N-methoxy-urea N-[3-triflu0romethyl-1,2,4-thiadiazolyl(5)]-l ethyl-N'-methyl-urea N- 3-dichlorome thyll ,2,4-thiadiazolyl(5 )]-N N-dimethyl-urea Arnaranthus Papaver retroflexus rhoeas 4. plants undamaged, as control plants dead 5. 9-2 intermediary stages of damage 6. N-[3-trifluoromethyl-1,2,4-oxadiazolyl(5 )]-N',N dimethvl-urea l5 7 Active Amount substance applied Lolium Alopecurus Seturiu Digituria No in kg/na multiflorum myosuroides italica sanguinalis Galium aparine Pastinaca sativa When the plants have reached the 4-leaf stade, they were treated with a 2 aqueous emulsion of the active substance to be tested. The trays are then kept in a 5 green-house at 25 to 28C and 40 5O humidity under daylight. The test was evaluated 15 days after the application of the active substance according to the following scale:

The 2 emulsion was prepared by diluting with water a 25 emulsion-concentrate of the following composition: 25 parts of active substance, 32.5 parts of isophoron,

623 1 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 l 1 1 ll I l l l l ll 42 32 93 8732 646477 423 2 3 42 32 1 765488889873 632242 434 323l l11 11 w h 8774865 o 899788776 9u 879876 w E w 9888988787 77339875 74 44 33 7732 a a .m 42 3 221 2 1879954 2 2 aw P 8654663 742 872 53 6632 11111 41. 432243 332 9887 ow mwm 5 5 5 5. 5 5 5 5 5 5 5 5 5 5 24 24 24 24 24 24 24 7.4 24 24 24 l2 Wl 1 A .m w W n 1 2 1 4 5 6 7 l 2 3 4 5 6 7 b u s The preceding tests demonstrate the broad range the herbicidal effect of the active substances accordir to the invention. In contrast thereto, known thiadiazt 32.5 parts of methyl ethyl ketone, 10 parts of a combination emulgator consisting of nonyl phenol-oxy ethylem: and dodecyl benzyl sulfonic acid-Ca-salt.

11 1 ureas, for example the -alk'yl-l,3,4-thiadiazolyl(2)- eas of Dutch patent specification open to public inection No. 68.13438 and the 1,'2,4-thiadiazolyl(5)- eas of Dutch patent specification open to public inection No. 68.13437 have only limited herbicidal efct even in application amounts of 5 kg per'hectare. For the preparation of herbicidal agents, the active bstances are mixed with suitable carriers and/or dis :rsing agents. To widen the range of action, these ;ents can be admixed with other herbicides, for exame triazines such as halogen-diamino-s-triazines, alvxyand alkylthiodiamino-s-triazines, triazoles, diaies such as uracils, aliphatic carboxylic acids and ilogen carboxylic acids, halogenated benzoic acids .d phenylacetic acids, aryloxyalkane carboxylic acids, 'drazides, amides, nitriles, esters of such carboxylic ids, carbamic and thiocarbamic acid esters, ureas,

The following examples illustrate the production of e new ureas. Other ureas of the Formula I which were oduced according to the procedures described in the amples are found in the table following. The temperures are given in degrees ,centigrade.

EXAMPLE 1 20 g of N-[3-trifluoromethyl-l,2,4-thiadiazolyl(5)]- -phenyl carbamate and 1 ml of triethyl amine are :ated under reflux in 200 ml of benzene. To the boilg solution there are added dropwise 5.4 g of methyl nine, dissolved in 50 ml of benzene. The reaction ixture is refluxed for 1 hour and then stirred for 12 IUI'S at room temperature. The precipitate is removed filtration and washed with benzene and the with pe- )leum ether. After drying and recrystallization from ethanol/water, the N-[ 3-trifluoromethyll ,2,4- iadiazolyl(5)]-N-methyl-urea has a melting point of 7-219C.

EXAMPLE 2 A solution of 14.9 g of cyclopropyl amine in 20 ml of. :nzene is added dropwise with stirring to a boiling sotion of 32 g of N-[3-trifluoromethyl-l,2,4- iadiazolyl(5)]-O-phenyl carbamate and 1.4 ml of trihyl amine in 300 ml of benzene. After refluxing for 1 hours, the solvent is concentrated by evaporation in cuo, and the residue is recrystallized from methanol/- iter. The N-[3-trichloromethyl-l,2,4- iadiazolyl(5)]-N-cyclopropyl-urea has a melting lint of l77"-180C.

EXAMPLE 3 1.8 ml of triethyl amine and 17.5 ml of methyl isocya- .te are added to a solution of 27 g of 3-trichlorometh- 'S-methyIamino-1,2,4-thiadiazole in 350 ml of acene and refluxed for 24 hours. The solvent is then re- Jved by distillation in vacuo, and the residue is reystallized from alcohol/water. The N-[3-triloromethyll ,2,4-thiadiazolyl( 5 -N,N '-dimethylea has a melting point of l46-l50C.

EXAMPLE 4 A solution of 3.2 g of a-amino-isobutyric acid nitrile d 4.75 ml of triethyl amine in 150 ml of benzene are ded dropwise to a boiling solution of g of N-[3-triloromethyl-l ,2,4-thiadiazolyl( 5 -N-methyl-carmoyl-chloride in 100 ml of benzene. The'reaction xture is refluxed for 16 hours. Thep'recipitate which parates is then removed and washed several times 12 with water. After recrystallization from dioxane, the N;[ 3-trichloromethyl-1 ,2,4-thiadiazolyl( 5 ]-N-methyl- N"-( 1""-m'ethyl 1'-cyano-ethy )-urea has a melting point of 255(with decomposition).

EXAMPLE 5 A mixture of 16.9 g of 3-trifluoromethyl-5 amino- 1,2,4-thiadiazole and 50 ml of dimethyl-carbamoyl chloride is stirred at a bath temperature of 160C for 5 hours. After this mixture has been allowed to cool it is poured into ice-water and the pH is adjusted to 5-6 by means of aqueous NaOl-l. An oil separates, which crystallizes after a short time. The precipitate is filtered, washed with water and then added while stirring to ml of 2N aqueous ammonia solution. The solution is filtered and the filtrate is added with aqueous hydrochloric acid until slightly acid. A precipitate forms, which is filtered and dried. After recrystallisation from benzene 8.5 g of N-[B-trifluoromethyl-l,2,4-thiadiazolyl(5)]- N',N'-dimethyl-urea melting point l24-126C is obtained.

EXAMPLE 6 Active substance melting point:

N-[3-trifluoromethyl-1,2,4-thiadiazolyl(5)]- N,N'-dimethyl-urea 148-152 N-[3-trich1oromethyl-1,2,4-thiadiazolyl(5)]- 13 3 N ,N '-dimethyl-urea N-I 3-trichloromethyll ,2,4-thiadiazolyl( 5 decomposition N'-methyl-urea N-[3-trichloromethyl-1,2,4-oxadiazolyl(5)]- decomposition continued Active substance melting point:

In the following are examples which are given to illustrate the production of the starting materials of Formula II and the production of the carbamic acid derivatives. In the table following, there are listed several oxadiazoles which have not been previously described as well as some phenyl carbamates.

EXAMPLE A A solution of 15.4 ml of triethyl amine in 25 ml of benzene are slowly added dropwise with stirringat 2530C to a suspension of 17.7 g of 2,2,2-trichloroacetamidoxime [J. Het. Chem. 3, 214 (1966)] and 11.6 g of cyanogen bromide in 200 ml of benzene. The reaction mixture is stirred for seven 1 hours at room temperature, the resultant yellow precipitate is then removed by filtration and washed thoroughly with water. After drying, 15.3 g of 3-trichloromethyl-5- amino-1,2,4-oxadiazole, having a melting point of 160-l63C, are obtained. After recrystallizing once from methanol/water, the melting point rises to 165-168.

EXAMPLE B 302.5 g of 3-trifluoromethyl-5-amino-1,2,4- thiadiazole (mp. 188190) are refluxed together with 271 ml of phenyl chloroformate and 27.7 ml of dimethyl formamide in 2 l of chlorobenzene for hours. Simultaneously dry nitrogen gas is introduced to remove the HCl gas which forms during the reaction. After cooling, the precipitate is removed and washed with chlorobenzene and petroleum ether. 355 g of N [3-trifluoromethyll ,2,4-thiadiazolyl(5 -Opheny carbamate, m.p. l81183C.

EXAMPLE C 44.2 ml of phenyl chloroformate are added dropwise at -30" with stirring to a solution of 58.4 gof 3-trifluoromethyl-S-methylaminol ,2,4-thiadiazole (A) (m.p. 124-l )and 49 ml of triethylamine in 600 ml of dioxane. After stirring at room temperature for several hours, the triethylamine hydrochloride which precipitates is separated and the filtrate is concentrated under vacuum. The residue crystallizes from isopropano]. The N-[3-trifluoromethyl-1,2,4-thiadiazolyl(5)]- N-methyl-O-phenyl carbamate has a melting point 127l29.

EXAMPLE D A mixture of 178.3 g of 3-trichloromethyl-f methylamino-l,2,4-thiadiazole and 2 l of absolute bei zene are heated under reflux while stirring. During period of 7 hours, 36 l of phosgene are then introduce into this reaction mixture. After this, the mixture stirred for another 2 hours at reflux temperature and 1 hours at room temperature. The reaction-mixture then concentrated in a rotatory-evaporator. The res due is recrystallized twice from cyclohexane to yiel 191 g of N-[3-trifluoromethyl-l,2,4-thiadiazolyl(5) N-methyl-carbamoyl-chloride, melting point 93-95.

EXAMPLE E To a stirred mixture of 138 g 3-trifluoromethyl-f amino-1,2,4-oxadiazole and 280 ml of triethylamine i 1.5 l of dioxam are added dropwise 253 ml of O-ph4 nyl-chloroformiate. The temperature of the reactio mixture rises to during this addition. The reactic mixture is stirred at room temperature during one nigl and the precipitated triethylamine-hydrochloride then filtered off. The filtrate is concentrated under vat uum and the residue is recrystallized from ClliSt propylether to yield 265 g of 3-trifluoromethyl-f (dicarbophenoxy-arnino 1,2,4-oxadiazole, meltir point 120l22C.

EXAMPLE F 255 g of 2,2,2-trifluoroacetamidoxim are introduce with stirring and cooling well to temperatures belo 40 into 890 ml of trichloroacetic anhydride. After tl exothermic reaction has subsided, the mixture is heate for 1% hours at After cooling, the reaction mi: ture is poured into ice water. The aqueous phase is e: tracted several time with ether; the ether extracts a1 combined with the organic phase and dried. After t1 solvent has been removed by distillation, the residue fractionated. The 3-trifluoromethyl-5-trichloromethy 1,2,4-oxadiazole has a boiling point of 42-44/ 1 Torr. i

A solution of 29.3 g of ammonia in 500 ml of meth: 1101 is added dropwise to a solution of 200 g of 3-t1 fluoromethyl-S-trichloromethyl- 1 ,2,4-oxadiazole (A in one liter of benzene. After the exothermic reactic has subsided, the mixture is stirred for 16 hours at roo temperature and then the solvent mixture is remove by distilling under vacuum. The crystalline residue made into a paste with a small amount of water at washed. The 3-trifluoromethyl-S-amino-1,2,- oxadiazole has a melting point of 103-105.

EXAMPLE G g of 3-trifluoromethyl-5-amino-1,2,4thiadiazo are dissolved in 2.5 l of methanol puriss, and the treated in the presence of 25 g Palladium-charcoal 5 at room temperature under atmospheric pressur After 20 hours the hydration ceases. The catalyst is f tered off and the filtrate is concentrated under vacuu until dryness. The residue is crystallized from ethanoi water and yields 59 g of 3-dichloromethyl-5-amin 1s The intermediary products listed below were preared according to the Examples A to G.

smpounds: melting point trifluoromethyl-amino-l,2,4-thiadiazole 188 190 trifluoromethyl-5-methylaminol .2.4-thiaazole 124 125 trichloromethyl-5-amino-1,2,4-thiadiazole 195 197 trichloromethyl-S-methylamino-1,2,4-lhiaazole 198 200 3-trifluoromethyll ,2,4-thiadiazole( 5 -methyl-carbamoyl-chloride 43 45 3-trichloromethyll ,2,4-thiadiazole( 5 -methyl-O-phenyLcarbamate 85 87 -[3-trichloromethyl-1,2,4-thiadiazole(5)]- -phenyl-carbamate 167 169 lrichloromethyL 1 .2,4-thiadiazoyl( 5 )-N- liyl-carbamoyl-chloride 23 25 trifluoromelhyl-1,2,4-thiadiazolyl(5)-N- hyl-carbamoyl-chloride 28 30 -[dich1oromethyll ,2,4-thiadiazolyl( 5 -methyl-carbamoyl-chloride 64 66 -[dichloromethyl-1.2,4-thiadiazolyl(5)] -phenyl-carbamate 168 170 trichloromethyl-S-methylamino-1,2,4- :adiazole 68 70 trifluoromethyI-S-methylamino-1,2,4-

radiazole 49 50 -[3-trifluoromethyl-l,2,4-oxadiazole(5 )1- -methyl-O-phenyl-carbamate 66 68 B-trichlorom ethyl- 1 ,2,4-oxadiazole( 5 -methyl-O-phenyl-carbamate 108 110 3-trichlorom ethyl 1 ,2,4-oxadiazole( 5 J -phenyl-carbamate 163 166 -[3-trichloromethyl-l,2,4-oxadiazole(5]]- -rnethyl-carbamoyl-chloride 49 50 The production of herbicidal agents according to the lvention is performed in a known manner by intimate lixing and grinding of active substances of the general;

ormula I together with suitable carriers, optionally ith the addition of dispersing agents or solvents, 'hich are inert'towards the active substances. The acve substances can be prepared, in the following forms: solid preparations: dusts, scattering agents, granurtes, (coated granulates, impregnated granulates and omogeneous granulates),

water dispersible concentrates of the active sub- :ance: Wettable powders,- pastes, emulsions;

liquid preparations: solutions.

To produce solid application forms (dusts, scattering gents, granulates), the active substances aremixed The particle size of the carriers is, for dusts advanta- :ously up to about 0.1 mm, for scattering agents from aout 0.075 to 0.2 mm, and for granulates 0.2 mm or Jarser.

The concentrations of active substance in the reparations are from 0.5 to 80%.

To these mixtures can also be added additives which abilize the active substance and/or non-ionic, anionic .solid 1d cationic surface active substances, which for examlants or parts of plants (adhesives and agglutinants) aromatic hydrocarbons, .there ofl'alkyl naphthalenes and mineral oils, alone or and/or ensure a better wettability (wetting agents) and dispersibility (dispersing agents). Examples of suitable adhesives are the following: olein/chalk mixture, cellulose derivatives (methyl cellulose, carboxymethyl cellulose), hydroxyethyl glycolethers of monoalkyl and dialkyl phenols having 5 to 15. ethylene oxide radicals per molecule and 8 to 9 carbon atoms in the alkyl radical, lignin sulfonic acid, their alkali metal and alkaline earth metal salts, polyethylene glycol ethers (carbowaxes), fatty alcohol polyglycol ethers having 5 to 20 ethylene oxide radicals per molecule and 8 to 18 carbon atoms in the fatty alcohol moiety, condensation products of ethylene oxide/propylene oxide, polyvinyl pyrrolidones, polyvinyl alcohols, condensation products of urea and formaldehyde, and also latex products.

The water-dispersible concentrates of the active substance, i.e., Wettable powders, pastes and emulsion concentrates, are agents which can be diluted with water to any concentration desired. They consist of active substance, carrier, optionally additives which stabilize the active substance, surface-active substances and anti-foam agents and, optionally, solvents. The concentration of active substance in these agents is 5 to Wettable powders and pastes are obtained by mixing and grinding the active substances with dispersing agents and pulverulent carriers in suitable'apparatus until homogeneity is attained. Carriers are, for example, those mentioned for the solid forms of application. In some cases it is advantageous to use mixtures of different carriers. As dispersing agents there can be used, for example, condensation products of sulfonated ,naphthalene and sulfonated naphthalene derivatives with formaldehyde, condensation products of naphthalene 'or naphthalene sulfonic acids with phenol and formaldehyde, as well as alkali, ammonium and alkaline earth metal salts of lignin sulfonic acid, in addition, alkylaryl sulfonates, alkali and alkaline earth metal salts of dibutyl naphthalene sulfonic acid, fatty alcohol duce emulsion concentrates and pastes, dispersing agents such as those given in the previous paragraphs, organic solvents and water are used. Examples of suitable solvents are the following: alcohols, benzene, xylenes, toluene, dimethyl sulfoxide, and'mineral oil fractions boiling between and 350C. The solvents must be practically odorless, not phytotoxic, inert to 'the'active substances and not readily inflammable.

Furthermore, the agents according to the invention "can be applied in the form of solutions. For this purpose the active substance or several active substances of general formula [are dissolved in suitable organic solvents, mixtures of solvents or in water, Aliphatic and chlorinated derivatives mixed with each other can be used as organic solvents. The solution should contain the active substances in a concentration of from. 1 to 20%.

The agents described according to the invention can be mixed with other biocidally active compounds or agents. Thus, to broaden the range of action, the new agents can contain, e.g., insecticides,- fungicides, bactericides, fungistatics, bacteriostatics or nematocides in addition to the compounds mentioned of the general Formula I. The agents according to the invention can also contain plant fertilizers, trace elements, etci In the following, forms of preparation of the new ureas are described. Parts" mean parts by weight.

GRAN ULATE The following ingredients are used to produce a granulate:

5 parts of N'[3-trifluoromethyl- 1 ,2,4- thiadiazolyl( 5 )]-N,N -dimethyl-urea,

0.25 part of epichlorohydrin,

0.25 part of cetyl polyglycol ether,

3.50 parts of polyethylene glycol 91 parts of kaolin (granular size 0.3 0.8 mm).

The active ingredient is mixed with epichlorohydrin and dissolved in 6 parts of acetone, then the polyethylene glycol and cetyl polyglycol ether are added. The resulting solution is sprayed onto the kaolin and then evaporated in vacuum.

WETTABLE POWDER The following components are used for the preparation of a. 50%, b) 25% and c) 10% wettable powders:

50 parts of N-[3-trifluoromethyl-1,2,4-

thiadiazolyl( 5 )]-N ,N '-dimethyl-urea,

5 parts of sodium dibutylnaphthyl sulphonate,

3 parts of naphthalene sulphonic acid/phenol sulphonic acid/formaldehyde condensation product 32:1,

parts of kaolin,

22 parts of Champagne chalk;

25 parts of N-[3-trifluoromethyl-1,2,4-

thiadiazolyl( 5 )]-N,N -dimethyl-urea,

5 parts of the sodium salt of oleoylmethyl tauride,

2.5 parts of naphthalene sulphonic acid/formaldehyde condensation product,

0.5 part of carboxymethyl cellulose,

5 parts of neutral potassium aluminum silicate,

62 parts of kaolin;

10 parts of N-[3-trichloromethyl-l,2,4- thiadiazolyl 5 )]-N-me thyl-N -cyclopropyl-urea,

3 parts of a mixture of sodium salts of saturated fatty alcohol sulphates,

5 parts of naphthalene sulphonic acid/formaldehyde condensation product,

82 parts of kaolin.

The given active ingredient is absorbed onto the corresponding carriers (kaolin and chalk) and then mixed and ground. Wettable powders having excellent wettability and suspensibility are obtained. By dilution with water, suspensions of any desired concentration of the active ingredients can be obtained from such wettable powders. Such suspensions are suitable for the control of weeds and wild grasses in cultivated plantations.

PA STE The following ingredients are used for the preparation of a 45% paste:

45 parts of N-[3-trifluoromethyl-l,2,

thiadiazolyl( 5 ]-N,N-dimethyl-urea,

5 parts of sodium aluminum silicate,

. 14 parts of cetyl polyglycol ether having 8 mol of et ylene oxide,

1 part of oleyl polyglycol ether having 8" mol of eth ene oxide, i

2 parts of 'spindleoil,

10 parts of polyethylene glycol,

' 23 parts of water. i i r The active ingredient is intimately mixed and grow in suitable equipment with the additives. A paste is o tained which can be diluted with water to prepare SL pensions of any desired concentration. The suspensio are suitable for the treatment of vegetable plantatior EMULSION CONCENTRATE To prepare a 10% emulsion concentrate 10 parts of N-[ 3-trifluoromethyl- 1 ,2,

thiadiazolyl( 5 )]-N' ,N '-dimethyl-urea, 15 parts of oleyl polyglycol ether having 8 mol of et ylene oxide, and parts of isophorone are mixed together. This concentrate can be dilut with water to form emulsions of suitable concentr tions. Such emulsions are suitable for the control weeds in cultivated plants such as cotton, maize, et

What we claim is: l. A herbicidal composition for combatting weeds crop cultures which comprises a herbicidally effecti amount of a compound of the formula wherein R represents a-halogen lower alkyl,

R and R each independently represents hydrogen lower alkyl,

R represents lower alkyl optionally substituted cyano or alkoxy of from 1 to 4 carbon atoms, c cloalkyl of from 3 to 10 carbon atoms, alkoxy from 1 to 4 carbon atoms, alkenyl or halogenoalk nyl of 3 or 4 carbon atoms, or alkynyl of 3 to 4 c; bon atoms, and

X represents oxygen or sulphur; together with a suitable carrier therefor.

2. The composition of claim 1, wherein in said co: pound X is sulphur.

3. The composition of claim 2, wherein said co: pound is N[3-trifluorornethyl-l,2,4-thiadiazolyl(5 N,N'-dimethyl-urea.

4. The composition of claim 2, wherein said co pound is N-[3-trifluoromethyl-l,2,4-thiadiazolyl(5 N, N-dimethyl-urea.

5. The composition of claim 2, wherein said co pound is N-[ 3-trifluoromethyll ,2,4-thiadiazolyl(5 N'-methyl-urea.

6. The composition of claim 2, wherein said co pound is N-[3-trifluoromethyl-l,2,4-thiadiazolyl(5 N-ethyl-N -methyl-urea.

7. The composition of claim 2, wherein said co pound is N-[3-dichloromethyl-l,2,4-thiadiazolyl(5 N'-methyl-urea.

8. The composition of claim 2, wherein said co pound is N-[3-dichloromethyl-l,2,4-thiadiazolyl(5 12. The composition of claim 11, wherein said compound is N-[ 3-trifluoromethyl- 1 ,2,4-oxadiazolyl(5 N',N-dimethyl-urea.

13. A method for combatting weeds in crop cultures which comprises applying to the crop area a herbicidally effective amount of a compound according to the formula of claim 1.

l4. The method of claim 13, wherein in said compound X is sulphur.

15. The method of claim 13, wherein in said compound X is oxygen. 

1. A HERBICIDAL COMPOSITION FOR COMBATING WEEDS IN CROP CULTURES WHICH COMPRISES A HERBICIDALLY EFFECTIVE AMOUNT OF A COMPOUND OF THE FORMULA
 2. The composition of claim 1, wherein in said compound X is sulphur.
 3. The composition of claim 2, wherein said compound is N-(3-trifluoromethyl-1,2,4-thiadiazolyl(5))-N,N''-dimethyl-urea.
 4. The composition of claim 2, wherein said compound is N-(3-trifluoromethyl-1,2,4-thiadiazolyl(5))-N'', N''-dimethyl-urea.
 5. The composition of claiM 2, wherein said compound is N-(3-trifluoromethyl-1,2,4-thiadiazolyl(5))-N''-methyl-urea.
 6. The composition of claim 2, wherein said compound is N-(3-trifluoromethyl-1,2,4-thiadiazolyl(5))-N-ethyl-N''-methyl-urea.
 7. The composition of claim 2, wherein said compound is N-(3-dichloromethyl-1,2,4-thiadiazolyl(5))-N''-methyl-urea.
 8. The composition of claim 2, wherein said compound is N-(3-dichloromethyl-1,2,4-thiadiazolyl(5))-N'', N''-dimethyl-urea.
 9. The composition of claim 2, wherein said compound is N-(3-dichloromethyl-1,2,4-thiadiazolyl(5))-N,N''-dimethyl-urea.
 10. The composition of claim 2, wherein said compound is N-(3-trifluoromethyl-1,2,4-thiadiazolyl(5))-N''-methyl-N''-methoxy-urea.
 11. The composition of claim 1, wherein in said compound X is oxygen.
 12. The composition of claim 11, wherein said compound is N-(3-trifluoromethyl-1,2,4-oxadiazolyl(5))-N'',N''-dimethyl-urea.
 13. A method for combatting weeds in crop cultures which comprises applying to the crop area a herbicidally effective amount of a compound according to the formula of claim
 1. 14. The method of claim 13, wherein in said compound X is sulphur.
 15. The method of claim 13, wherein in said compound X is oxygen. 